The invention relates to a fluid-pressure-controlled, pilot-operated solenoid valve apparatus, especially such a solenoid valve apparatus which is suitably operable in an environment requiring a precise and timely control of fluid pressure flow therethrough. One use of such a fast-acting, precisely-controlled solenoid valve apparatus could be on an anti-skid braking system which operates to release fluid pressure from a brake cylinder upon sensing an excessive amount of wheel slip. An example of such a system including a solenoid valve can be found in Great Britain Pat. No. 1416204, wherein is disclosed a solenoid valve having inlet and outlet valve portions connnected partially in series such that, venting of fluid pressure to atmosphere during a brake release operation is dissipated within the apparatus so as to prevent excessive noise being generated thereby. A disadvantage that this known device exhibits is that the response time of the membrane which forms part of the inlet and outlet valves is not fast and therefore requires a bias spring to effect rapid valve closure, such bias spring thereafter serving to further slow valve opening since sufficient fluid pressure must be introduced to overcome the bias spring force.
Additionally, known solenoid valves employing a membrane separating a control valve from either the inlet or outlet valve have exhausted the fluid pressure which operates the control portion of the valve, to atmosphere.
Of course, the fast-acting, precisely-controlled solenoid valve apparatus has numerous applications in addition to the above-mentioned wheel skid arrangement, such additional applications as will become evident upon a complete reading of the disclosure.